<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            width: 100px;
            height: 100px;
            border: 1px solid #000;
            overflow: hidden;
        }
        .box::before{
            content: attr(data-info);
            height: 20px;
            width: 100px;
            background: skyblue;
            color: #fff;
            line-height: 20px;
            text-align: center;
            display: inline-block;
            transform: rotate(-45deg) translate(-26px,-10px);
        }
    </style>
</head>
<body>
    <div class="box" data-info="打一折"></div>
    <div class="box" data-info="打二折"></div>
    <div class="box" data-info="打三折"></div>
    <div class="box" data-info="打四折"></div>
    <div class="box" data-info="打五折"></div>
</body>
</html>